1. Field of the Invention
The invention relates to a disk recording and/or reproducing device having a configuration that a disk housing portion of a disk tray, having a concave shape for housing a disk-like recording medium, is covered by a disk cover.
2. Description of the Related Art
A known disk recording and/or reproducing device of this sort is disclosed, for example, in Japanese Unexamined Patent Application Publication No. 2003-68051 . Japanese Unexamined Patent Application Publication No. 2003-68051 discloses an optical disk device including a disk drive device capable of preventing occurrence of vibration when a disk is rotated at a high speed. The optical disk device disclosed in Japanese Unexamined Patent Application Publication No. 2003-68051 is “an optical disk device having a configuration in which a disk is placed on a disk placement portion of a tray in a non-operating position and thereafter, when the tray is shifted to an operating position, the disk is placed on a turn table”, and the disk drive device of the optical disk device is characterized in that “a disk-like cover for covering a disk surface when the tray is in the operating position is provided over the disk”.
According to the disk drive device of the optical disk device having the above-described configuration (hereinafter referred to as the “first related art”), such an effect is expected that “since the affect of air current to disk rotation can be minimized, the disk rotation characteristic can be improved” (paragraph [0019] of the specification).
Another known disk recording and/or reproducing device is disclosed, for example, in Japanese Unexamined Patent Application Publication No. 09-17082 . Japanese Unexamined Patent Application Publication No. 09-17082 discloses an optical disk drive device that suppresses attachment of dust to an optical disk recording medium and an optical pickup as much as possible. The optical disk drive device disclosed in Japanese Unexamined Patent Application Publication No. 09-17082 is “a tray-loading-type optical disk drive device having a disk tray that slides on a front surface and an interior surface of a case, in a horizontal direction, through a front opening portion of the case, so as to be freely put in and drawn out from the case, while an optical disk recording medium is being placed thereon in a detachable manner”, and the disk drive device is characterized in “including a cover for covering the optical disk recording medium from a top surface through a side surface thereof when the disk tray is housed in the case in a space relative to the disk tray, and a driving mechanism for suppressedly biasing the cover from above to the disk tray”.
According to the optical disk drive device having the above-described configuration (hereinafter referred to as the “second related art”), such an effect is expected that “the attachment of dust to an optical disk recording medium and an optical pickup can be remarkably reduced while adopting a tray-loading-type optical disk device” (paragraph [0032] of the specification).
FIG. 1 is a diagram for explaining the above-described first related art. In FIG. 1, a reference numeral 100 denotes a disk, a reference numeral 101 denotes a tray, a reference numeral 102 denotes a disk-like cover, and a reference numeral 103 denotes a support member. The tray 101 includes a disk housing portion 104 formed in a circular concave shape in which and from which the disk 100 can be placed and taken out. In the disk housing portion 104, the disk 100 is placed on a not-shown turn table and is rotatably supported. All of the disk housing portion 104 is covered by the disk-like cover 102.
Although not shown, the disk-like cover 102 is rotatably supported by a support member 103 together with a clamp member placed to face the turn table. An outer periphery of the disk-like cover 102 is provided with a side surface portion 102a continuously formed in an annular shape. A continuous ring-shaped tip end face of the side surface portion 102a of the disk-like cover 102 is brought into contact with a circumference of the disk housing portion 104 provided on a main surface of the tray 101.
In the first related art, the disk-like cover 102 for covering a disk surface of the disk 100 is provided above the disk 100 to control the air current involved in disk rotation, and thereby an affect given to disk rotation by the air current is minimized and the disk rotation characteristic is enhanced. However, since the continuous ring-shaped tip end face of the side surface portion 102a of the disk-like cover 102 is opposed to the main surface of the tray 101 and the area of the tip end face of the side surface portion 102a is relatively small, a space tends to be created between the tip end face of the side surface portion 102a of the disk-like cover 102 and the main surface of the tray 101. Accordingly, the air current involved in a rotation of the disk 100 flows through the space between the side surface portion 102a of the disk-like cover 102 and the main surface of the tray 101, resulting in causing a problem that a noise level due to the air current becomes relatively high.
In the second related art, although a disk-like cover for covering the optical disk placed on the disk tray from the top through the side portion is provided to prevent invasion of dust with the cover, the circumference portion of the cover is bent downwardly to have the end surface of the circumference portion opposed to the main surface of the tray. Therefore, as in the first related art, due to a small area of the end surface of the circumference portion of the cover opposed to the main surface of the tray, a space tends to be created between the circumference portion of the cover and the main surface of the tray 101. As a result, the air current involved in disk rotation flows through the space between the circumference portion of the cover and the main surface of the tray 101 to similarly cause a problem of a high noise level due to the air current.